tipc: remove two indentation levels in tipc_recv_msg routine

The message dispatching part of tipc_recv_msg() is wrapped layers of
while/if/if/switch, causing out-of-control indentation and does not
look very good. We reduce two indentation levels by separating the
message dispatching from the blocks that checks link state and
sequence numbers, allowing longer function and arg names to be
consistently indented without wrapping. Additionally we also rename
"cont" label to "discard" and add one new label called "unlock_discard"
to make code clearer. In all, these are cosmetic changes that do not
alter the operation of TIPC in any way.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Cc: David Laight <david.laight@aculab.com>
Cc: Andreas Bofjäll <andreas.bofjall@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/link.c

@@ -1507,15 +1507,15 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 
 		/* Ensure bearer is still enabled */
 		if (unlikely(!b_ptr->active))
-			goto cont;
+			goto discard;
 
 		/* Ensure message is well-formed */
 		if (unlikely(!link_recv_buf_validate(buf)))
-			goto cont;
+			goto discard;
 
 		/* Ensure message data is a single contiguous unit */
 		if (unlikely(skb_linearize(buf)))
-			goto cont;
+			goto discard;
 
 		/* Handle arrival of a non-unicast link message */
 		msg = buf_msg(buf);
@@ -1531,20 +1531,18 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 		/* Discard unicast link messages destined for another node */
 		if (unlikely(!msg_short(msg) &&
 			     (msg_destnode(msg) != tipc_own_addr)))
-			goto cont;
+			goto discard;
 
 		/* Locate neighboring node that sent message */
 		n_ptr = tipc_node_find(msg_prevnode(msg));
 		if (unlikely(!n_ptr))
-			goto cont;
+			goto discard;
 		tipc_node_lock(n_ptr);
 
 		/* Locate unicast link endpoint that should handle message */
 		l_ptr = n_ptr->links[b_ptr->identity];
-		if (unlikely(!l_ptr)) {
-			tipc_node_unlock(n_ptr);
-			goto cont;
-		}
+		if (unlikely(!l_ptr))
+			goto unlock_discard;
 
 		/* Verify that communication with node is currently allowed */
 		if ((n_ptr->block_setup & WAIT_PEER_DOWN) &&
@@ -1554,10 +1552,8 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 			!msg_redundant_link(msg))
 			n_ptr->block_setup &= ~WAIT_PEER_DOWN;
 
-		if (n_ptr->block_setup) {
-			tipc_node_unlock(n_ptr);
-			goto cont;
-		}
+		if (n_ptr->block_setup)
+			goto unlock_discard;
 
 		/* Validate message sequence number info */
 		seq_no = msg_seqno(msg);
@@ -1593,98 +1589,97 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 
 		/* Now (finally!) process the incoming message */
 protocol_check:
-		if (likely(link_working_working(l_ptr))) {
-			if (likely(seq_no == mod(l_ptr->next_in_no))) {
-				l_ptr->next_in_no++;
-				if (unlikely(l_ptr->oldest_deferred_in))
-					head = link_insert_deferred_queue(l_ptr,
-									  head);
-deliver:
-				if (likely(msg_isdata(msg))) {
-					tipc_node_unlock(n_ptr);
-					tipc_port_recv_msg(buf);
-					continue;
-				}
-				switch (msg_user(msg)) {
-					int ret;
-				case MSG_BUNDLER:
-					l_ptr->stats.recv_bundles++;
-					l_ptr->stats.recv_bundled +=
-						msg_msgcnt(msg);
-					tipc_node_unlock(n_ptr);
-					tipc_link_recv_bundle(buf);
-					continue;
-				case NAME_DISTRIBUTOR:
-					n_ptr->bclink.recv_permitted = true;
-					tipc_node_unlock(n_ptr);
-					tipc_named_recv(buf);
-					continue;
-				case BCAST_PROTOCOL:
-					tipc_link_recv_sync(n_ptr, buf);
-					tipc_node_unlock(n_ptr);
-					continue;
-				case CONN_MANAGER:
-					tipc_node_unlock(n_ptr);
-					tipc_port_recv_proto_msg(buf);
-					continue;
-				case MSG_FRAGMENTER:
-					l_ptr->stats.recv_fragments++;
-					ret = tipc_link_recv_fragment(
-						&l_ptr->defragm_buf,
-						&buf, &msg);
-					if (ret == 1) {
-						l_ptr->stats.recv_fragmented++;
-						goto deliver;
-					}
-					if (ret == -1)
-						l_ptr->next_in_no--;
-					break;
-				case CHANGEOVER_PROTOCOL:
-					type = msg_type(msg);
-					if (link_recv_changeover_msg(&l_ptr,
-								     &buf)) {
-						msg = buf_msg(buf);
-						seq_no = msg_seqno(msg);
-						if (type == ORIGINAL_MSG)
-							goto deliver;
-						goto protocol_check;
-					}
-					break;
-				default:
-					kfree_skb(buf);
-					buf = NULL;
-					break;
-				}
+		if (unlikely(!link_working_working(l_ptr))) {
+			if (msg_user(msg) == LINK_PROTOCOL) {
+				link_recv_proto_msg(l_ptr, buf);
+				head = link_insert_deferred_queue(l_ptr, head);
+				tipc_node_unlock(n_ptr);
+				continue;
+			}
+
+			/* Traffic message. Conditionally activate link */
+			link_state_event(l_ptr, TRAFFIC_MSG_EVT);
+
+			if (link_working_working(l_ptr)) {
+				/* Re-insert buffer in front of queue */
+				buf->next = head;
+				head = buf;
 				tipc_node_unlock(n_ptr);
-				tipc_net_route_msg(buf);
 				continue;
 			}
+			goto unlock_discard;
+		}
+
+		/* Link is now in state WORKING_WORKING */
+		if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
 			link_handle_out_of_seq_msg(l_ptr, buf);
 			head = link_insert_deferred_queue(l_ptr, head);
 			tipc_node_unlock(n_ptr);
 			continue;
 		}
-
-		/* Link is not in state WORKING_WORKING */
-		if (msg_user(msg) == LINK_PROTOCOL) {
-			link_recv_proto_msg(l_ptr, buf);
+		l_ptr->next_in_no++;
+		if (unlikely(l_ptr->oldest_deferred_in))
 			head = link_insert_deferred_queue(l_ptr, head);
+deliver:
+		if (likely(msg_isdata(msg))) {
 			tipc_node_unlock(n_ptr);
+			tipc_port_recv_msg(buf);
 			continue;
 		}
-
-		/* Traffic message. Conditionally activate link */
-		link_state_event(l_ptr, TRAFFIC_MSG_EVT);
-
-		if (link_working_working(l_ptr)) {
-			/* Re-insert buffer in front of queue */
-			buf->next = head;
-			head = buf;
+		switch (msg_user(msg)) {
+			int ret;
+		case MSG_BUNDLER:
+			l_ptr->stats.recv_bundles++;
+			l_ptr->stats.recv_bundled += msg_msgcnt(msg);
+			tipc_node_unlock(n_ptr);
+			tipc_link_recv_bundle(buf);
+			continue;
+		case NAME_DISTRIBUTOR:
+			n_ptr->bclink.recv_permitted = true;
+			tipc_node_unlock(n_ptr);
+			tipc_named_recv(buf);
+			continue;
+		case BCAST_PROTOCOL:
+			tipc_link_recv_sync(n_ptr, buf);
 			tipc_node_unlock(n_ptr);
 			continue;
+		case CONN_MANAGER:
+			tipc_node_unlock(n_ptr);
+			tipc_port_recv_proto_msg(buf);
+			continue;
+		case MSG_FRAGMENTER:
+			l_ptr->stats.recv_fragments++;
+			ret = tipc_link_recv_fragment(&l_ptr->defragm_buf,
+						      &buf, &msg);
+			if (ret == 1) {
+				l_ptr->stats.recv_fragmented++;
+				goto deliver;
+			}
+			if (ret == -1)
+				l_ptr->next_in_no--;
+			break;
+		case CHANGEOVER_PROTOCOL:
+			type = msg_type(msg);
+			if (link_recv_changeover_msg(&l_ptr, &buf)) {
+				msg = buf_msg(buf);
+				seq_no = msg_seqno(msg);
+				if (type == ORIGINAL_MSG)
+					goto deliver;
+				goto protocol_check;
+			}
+			break;
+		default:
+			kfree_skb(buf);
+			buf = NULL;
+			break;
 		}
 		tipc_node_unlock(n_ptr);
-cont:
+		tipc_net_route_msg(buf);
+		continue;
+unlock_discard:
+
+		tipc_node_unlock(n_ptr);
+discard:
 		kfree_skb(buf);
 	}
 	read_unlock_bh(&tipc_net_lock);